#hyl
import contextlib
from copy import deepcopy
from pathlib import Path

import torch
import torch.nn as nn

import math
#hyl
import numpy as np
#hyl
from ultralytics.nn.modules import (AIFI, C1, C2, C3, C3TR, SPP, SPPF, Bottleneck, BottleneckCSP, C2f, C3Ghost, C3x,
                                    Classify, Concat, Conv, Conv2, ConvTranspose, Detect, DWConv, DWConvTranspose2d,
                                    Focus, GhostBottleneck, GhostConv, HGBlock, HGStem, Pose, RepC3, RepConv,
                                    RTDETRDecoder, Segment)
#hyl
class MHSA(nn.Module):
    def __init__(self, n_dims, width=14, height=14, heads=4, pos_emb=False):
        super(MHSA, self).__init__()
 
        self.heads = heads
        self.query = nn.Conv2d(n_dims, n_dims, kernel_size=1)
        self.key = nn.Conv2d(n_dims, n_dims, kernel_size=1)
        self.value = nn.Conv2d(n_dims, n_dims, kernel_size=1)
        self.pos = pos_emb
        if self.pos:
            self.rel_h_weight = nn.Parameter(torch.randn([1, heads, (n_dims) // heads, 1, int(height)]),
                                             requires_grad=True)
            self.rel_w_weight = nn.Parameter(torch.randn([1, heads, (n_dims) // heads, int(width), 1]),
                                             requires_grad=True)
        self.softmax = nn.Softmax(dim=-1)
 
    def forward(self, x):
        n_batch, C, width, height = x.size()
        q = self.query(x).view(n_batch, self.heads, C // self.heads, -1)
        k = self.key(x).view(n_batch, self.heads, C // self.heads, -1)
        v = self.value(x).view(n_batch, self.heads, C // self.heads, -1)
        # print('q shape:{},k shape:{},v shape:{}'.format(q.shape,k.shape,v.shape))  #1,4,64,256
        content_content = torch.matmul(q.permute(0, 1, 3, 2), k)  # 1,C,h*w,h*w
        # print("qkT=",content_content.shape)
        c1, c2, c3, c4 = content_content.size()
        if self.pos:
            # print("old content_content shape",content_content.shape) #1,4,256,256
            content_position = (self.rel_h_weight + self.rel_w_weight).view(1, self.heads, C // self.heads, -1).permute(
                0, 1, 3, 2)  # 1,4,1024,64
 
            content_position = torch.matmul(content_position, q)  # ([1, 4, 1024, 256])
            content_position = content_position if (
                        content_content.shape == content_position.shape) else content_position[:, :, :c3, ]
            assert (content_content.shape == content_position.shape)
            # print('new pos222-> shape:',content_position.shape)
            # print('new content222-> shape:',content_content.shape)
            energy = content_content + content_position
        else:
            energy = content_content
        attention = self.softmax(energy)
        out = torch.matmul(v, attention.permute(0, 1, 3, 2))  # 1,4,256,64
        out = out.view(n_batch, C, width, height)
        return out
 
 
class BottleneckTransformer(nn.Module):
    # Transformer bottleneck
    # expansion = 1
 
    def __init__(self, c1, c2, stride=1, heads=4, mhsa=True, resolution=None, expansion=1):
        super(BottleneckTransformer, self).__init__()
        c_ = int(c2 * expansion)
        self.cv1 = Conv(c1, c_, 1, 1)
        # self.bn1 = nn.BatchNorm2d(c2)
        if not mhsa:
            self.cv2 = Conv(c_, c2, 3, 1)
        else:
            self.cv2 = nn.ModuleList()
            self.cv2.append(MHSA(c2, width=int(resolution[0]), height=int(resolution[1]), heads=heads))
            if stride == 2:
                self.cv2.append(nn.AvgPool2d(2, 2))
            self.cv2 = nn.Sequential(*self.cv2)
        self.shortcut = c1 == c2
        if stride != 1 or c1 != expansion * c2:
            self.shortcut = nn.Sequential(
                nn.Conv2d(c1, expansion * c2, kernel_size=1, stride=stride),
                nn.BatchNorm2d(expansion * c2)
            )
        self.fc1 = nn.Linear(c2, c2)
 
    def forward(self, x):
        out = x + self.cv2(self.cv1(x)) if self.shortcut else self.cv2(self.cv1(x))
        return out
 
 
class BoTNet(nn.Module):
    # CSP Bottleneck with 3 convolutions
    def __init__(self, c1, c2, n=1, e=0.5, e2=1, w=20, h=20):  # ch_in, ch_out, number, , expansion,w,h
        super(BoTNet, self).__init__()
        c_ = int(c2 * e)  # hidden channels
        self.cv1 = Conv(c1, c_, 1, 1)
        self.cv2 = Conv(c1, c_, 1, 1)
        self.cv3 = Conv(2 * c_, c2, 1)  # act=FReLU(c2)
        self.m = nn.Sequential(
            *[BottleneckTransformer(c_, c_, stride=1, heads=4, mhsa=True, resolution=(w, h), expansion=e2) for _ in
              range(n)])
        # self.m = nn.Sequential(*[CrossConv(c_, c_, 3, 1, g, 1.0, shortcut) for _ in range(n)])
#hyl
    def forward(self, x):
        return self.cv3(torch.cat((self.m(self.cv1(x)), self.cv2(x)), dim=1))